Barcodes, RFIDs (Radio Frequency IDentifiers), etc., are used conventionally to control the position information of articles in a warehouse, etc. For example, there is a method in which a barcode mounted to a shelf on which an article is stored is read to refer to the position information of the shelf corresponding to the identification information of the barcode; and the position information is used as the storage location of the article.
However, this method cannot be used for a rack-less placement zone, etc., in which the location where the article is stored is not suited to mounting a barcode or a RFID. Accordingly, in such a case, it is necessary for the worker to input the storage location of the article manually, reducing the operational efficiency.